JPH09145190A - Air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform the efficient and economical operation by flowing the refrigerant of appropriate amount to a circuit during the operation when a utilization side unit with the operation and the OFF operation is available. SOLUTION: Decompression devices 6a, 6b and flow passage opening/closing valves 14a, 14b are arranged in circuit 7a, 7b to be connected to a plurality of utilization side units 8a, 8b, and a valve control device 20 controls that the valve 14b to eliminate storage of the refrigerant when high temperature is detected by a temperature sensor 15a in the heating mode and in the cooling mode under the condition that the utilization side unit 8a is operated and the utilization side unit 8b is stopped is closed and a decompression device 6b is opened, and controls that the valve 14b to eliminate excessive refrigerant when low temperature is detected by a temperature sensor 15, and a part of the decompression device 6b is opened.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner capable of heating / cooling a plurality of use side units (indoor units) with a single heat source side unit (outdoor unit), and particularly to operating side and non-operating side. The present invention relates to an air conditioner in which, when there is a unit, the amount of circulation of a refrigerant medium is appropriately controlled to enable efficient and economical operation.

[0002]

2. Description of the Related Art FIG. 3 shows a conventional refrigerating circuit of an air conditioner capable of cooling and heating operation as described above, and the refrigerating circuit is divided by a vertical line N in the center for the sake of convenience. The heat source side unit 30 having the side heat exchanger 3, the pressure reducing device 6a, and the four-way valve 2 which is a flow path switching valve, and the first use side unit 31 having the use side heat exchanger 8a shown in the right region. It is installed separately in and. Further, in addition to the first user side unit 31, at least one other user side unit is provided. That is, in the embodiment, the second utilization side heat exchanger 8b is mounted on the second utilization side heat exchanger 8b in the refrigerant circuit on the heat utilization side. It is connected and mounted in parallel with the container 8a.

Then, by switching the flow path switching valve 2 between the solid line state and the broken line state, the refrigerant becomes the first utilization side unit 3
The first and second usage side units 32 flow in the directions of solid arrows during cooling, and in the directions of broken arrows during heating, respectively,
The heat exchange effect of heating is performed. At this time, in order to control the flow of the refrigerant to the usage-side heat exchanger 8a of the first usage-side unit 31, the pressure reducing device 6a is arranged in the pipeline 4a in the heat source side refrigeration circuit.

Similarly, in order to control the flow of the refrigerant to the use side heat exchanger 8b of the second use side unit 32, the second pressure reducing device 6b is provided with a pipeline in the refrigeration circuit on the heat source side. 4b. Therefore, this pressure reducing device 6a
And 6b are operated so that an appropriate amount of refrigerant can be flowed by controlling the throttling degree so that the first cooling unit 31 and the second cooling unit 32 can obtain predetermined cooling and heating capacities. There is.

[0005]

However, conventionally, the refrigerant circuit for flowing the refrigerant to each of the use side heat exchangers 8a and 8b of the first use side unit 31 and the second use side unit 32 branches the refrigerant. Since only one pressure reducing device 6a, 6b is arranged in each of the pipelines 4a, 4b, for example, when there is two heating-side heat exchangers 8a, 8b during heating, the heating-side heat exchanger 8a is When operating and the usage-side heat exchanger 8b is out of operation, the high-temperature refrigerant (arrow h) from the compressor also flows into the refrigerant path 7b during the out-of-operation, and the usage-side heat exchange is gradually performed. It will collect in the container 8b and the refrigerant path 7b. If there is such a pool of refrigerant,
Since a larger amount of refrigerant is generally required during heating than during cooling, there may be a case where a predetermined heating capacity cannot be output due to a shortage of refrigerant flowing through the operating side heat exchanger 8a during operation.

Similarly, at the time of cooling, the two heat exchangers 8a and 8b on the use side are operated at first, and the heat exchangers 1
When only the stand is operated, for example, the usage-side heat exchanger 8a, the refrigerant also flows through the pressure-reduction device 6b having an appropriate throttling degree to the usage-side heat exchanger 8b which is not in operation, and the usage-side heat exchange on the operation side is performed. There is a concern that the refrigerant cannot be sufficiently supplied to the container 8a.

Further, when cooling is performed by one use side heat exchanger, for example, the use side heat exchanger 8a, after the cooling progresses and reaches the set temperature (low temperature), the refrigerant is kept above the set temperature. It becomes an uneconomical operation due to excessive refrigerant flow.
Such a problem occurs in the past when the decompression device simply reduces the degree of throttling when the system is not in operation, and only performs a fixed throttling operation that does not respond to the temperature of the heat exchanger on the use side during operation. This is because the refrigeration circuit does not have a function of freely adjusting the throttling degree to bypass the refrigerant.

The present invention has been made in view of the above points, and a flow passage opening / closing valve is added to the refrigeration circuit to each usage side unit in addition to the pressure reducing device, so that a plurality of usage side units operate and operate. When operating in a mixed state of suspension, it is possible to adjust the refrigerant flow rate to the usage side unit during suspension of operation by the linked operation by the pressure reducing device and the flow path opening / closing valve, and output the required output to the operating side unit. It is an object of the present invention to provide an air conditioner capable of performing operational control so that the above can be exhibited and efficient and economical operation can be performed.

[0009]

In order to achieve the above object, the invention of claim 1 is a refrigerant pipe in which a compressor, a heat source side heat exchanger, a pressure reducing device, a use side heat exchanger, and a flow passage opening / closing valve are arranged in this order. In an air conditioner equipped with a refrigerant circuit that is annularly connected by
The refrigerant circuit is separated into a heat source side unit having the compressor, the heat source side heat exchanger, the pressure reducing device, and the flow path opening / closing mechanism, and a first use side unit having the use side heat exchanger. And at least one unit of a second usage side unit having a second usage side heat exchanger mounted therein, the second usage side heat exchanger being in parallel with the usage side heat exchanger in the refrigerant circuit. And a second pressure reducing device and a second flow path on-off valve in the refrigerant circuit of the heat source side unit so as to control the flow of the refrigerant to the second utilization side heat exchanger. The flow path on-off valve of the usage-side heat exchanger that is provided corresponding to the pressure reducing device and the flow-path opening / closing valve, and further responds when the condensation operation of the refrigerant is detected by the usage-side heat exchanger of the usage-side unit that is not in operation And then after a certain period of time, adequately install the corresponding decompression device. Opening is obtained by such a valve control device.

Further, the invention of claim 2 is an air conditioner equipped with a refrigerant circuit in which a compressor, a heat source side heat exchanger, a pressure reducing device, a utilization side heat exchanger, and a flow path opening / closing valve are annularly connected in order by a refrigerant pipe. In the heat source side unit having the compressor, the heat source side heat exchanger, the pressure reducing device, and the flow path opening / closing mechanism, and the first use side unit having the use side heat exchanger. At least one unit of a second usage-side unit that is separately mounted on the second usage-side heat exchanger and that mounts a second usage-side heat exchanger in the refrigerant circuit. While connecting in parallel,
A second pressure reducing device and a second flow passage opening / closing valve are provided in the refrigerant circuit of the heat source side unit so as to control the flow of the refrigerant to the second use side heat exchanger. It is installed corresponding to the valve, and when the user side heat exchanger of the operation side unit that is out of operation detects the evaporating action of the refrigerant, first open the flow path opening / closing valve of the corresponding user side heat exchanger and then respond after a predetermined time. The pressure reducing device is provided with a valve control device that partially opens.

Further, the invention of claim 3 is an air conditioner equipped with a refrigerant circuit comprising a compressor, a heat source side heat exchanger, a pressure reducing device, a utilization side heat exchanger, and a flow path opening / closing valve, which are sequentially annularly connected by a refrigerant pipe. A heat source side unit in which the compressor, the heat source side heat exchanger, the pressure reducing device, and the flow path opening / closing mechanism are mounted in the refrigerant circuit; and a first side in which the use side heat exchanger is mounted.
At least one second usage-side unit that is mounted separately from the usage-side unit and that mounts the second usage-side heat exchanger.
The unit is connected so that the second usage-side heat exchanger is parallel to the usage-side heat exchanger in the refrigerant circuit, and the second usage-side heat exchanger is included in the refrigerant circuit of the heat source-side unit. A second pressure reducing device and a second flow passage opening / closing valve are provided corresponding to the pressure reducing device and the flow passage opening / closing valve so as to control the flow of the refrigerant to the use side heat of the use side unit in operation. A valve that opens the flow path opening / closing valve of the user-side heat exchanger that is not in operation and then partially opens the decompression device of the user-side heat exchanger that is not in operation after detecting evaporating action of the refrigerant in the exchanger. A control device is provided.

Further, the invention of claim 4 is an air conditioner comprising a refrigerant circuit comprising a compressor, a heat source side heat exchanger, a pressure reducing device, a utilization side heat exchanger, and a flow passage opening / closing mechanism which are sequentially annularly connected by a refrigerant pipe. In the machine, at least one refrigerant circuit in which a second pressure reducing device, a second use side heat exchanger, and a second flow path opening / closing mechanism are sequentially connected in series by a refrigerant pipe is connected in parallel with the use side heat exchanger. At the same time, based on the temperature of the use-side heat exchanger or the refrigerant flowing through the use-side heat exchanger and the temperature of the second use-side heat exchanger or the refrigerant flowing through the use-side heat exchanger, the pressure reducing device and the second The decompression device is provided with a valve control device for controlling the opening from the fully open state to the fully closed state and the fully closed or fully opened state of the flow path opening / closing mechanism and the second flow path opening / closing mechanism.

According to a fifth aspect of the present invention, the pressure reducing device, the second pressure reducing device, the flow passage opening / closing mechanism, and the second flow passage opening / closing mechanism all open the flow passage of the refrigerant in response to a signal. It is designed to control from full closing to full closing.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. It should be noted that the same or corresponding components as those of the conventional device are designated by the same reference numerals.

In FIG. 2 showing the refrigeration cycle during cooling, the first
In the refrigeration circuit on the heat source side, in which a pipe is formed to flow the refrigerant to the use side unit 31, the pressure reducing equipment value 6a is arranged in the pipeline 4a through which the refrigerant branches and is discharged. In addition, the refrigerant after heat exchange that has flowed into the first usage-side unit 31 and evaporated passes through the usage-side refrigerant circuit 7a and returns to the compressor 1 in the branched pipe 9a on the heat source side, which is an electromagnetically-operated flow. A passage opening / closing valve 14a is provided.

Also, in the refrigeration circuit on the heat source side where a pipe is formed for flowing the refrigerant to the second use side unit 32, the pipeline 4b for branching and discharging the refrigerant also corresponds to the reduced pressure equipment value 6a. Then, the second reduced pressure equipment value 6b is provided. Then, the heat-exchanged refrigerant that has flowed into the second usage-side unit 32 and evaporated and returns to the compressor 1 via the usage-side refrigerant circuit 7b is branched to the heat source-side branched piping 9b. The refrigeration circuit has a second flow passage opening / closing valve 14b arranged so as to correspond to the flow passage opening / closing valve 14a.

Then, the refrigerant lines 7a and 7b of each of the use side units 31 and 32, the branched lines 4a and 4b for discharging the refrigerant on the heat source side, and the branched line 9 for sucking the refrigerant.
A and 9b are connected by a connection valve 17 and a service valve 18 to form a refrigerant circuit.

As described above, the pressure reduction values 6a and 6b can be freely adjusted and set from the fully closed state to the fully opened state. Further, the flow path opening / closing valves 14a and 14b are connected to the conduit 9
It is also possible to open and close whether to close or open a and 9b, and to adjust and set from fully closed to fully open.

By the way, in the first use side unit 31, a temperature sensor 15a for detecting the temperature of the refrigerant discharged from the use side heat exchanger 8a is provided in close contact with the refrigerant pipe 7a. Further, the temperature sensor 15a can be directly attached to the use side heat exchanger 8a to indirectly detect the refrigerant temperature by detecting the temperature of the use side heat exchanger 8a itself.

Similarly, also in the second usage side unit 32, a temperature sensor 15b for detecting the temperature of the refrigerant discharged from the usage side heat exchanger 8b is provided in close contact with the refrigerant pipe 7a, and the temperature sensor 15b is provided. Even if the sensor 15b is directly attached to the utilization side heat exchanger 8b, the refrigerant temperature can be detected. And these temperature sensors 15a,
When the temperature of 15b is detected in a certain temperature band, the detection signal is received and each flow path opening / closing valve 1 in each pipeline is received.
A valve control device 20 is provided in the heat source side unit for controlling 4a, 14b and the reduced pressure equipment values 6a, 6b so as to perform linked valve control as described later.

Also, if the four-way valve 2 is switched in this refrigeration cycle, the refrigerant becomes a reverse flow in the direction of the dotted arrow as shown in FIG.

Now, a valve control system, which is a feature of the present invention, will be described in which the flow path opening / closing valves 14a and 14b and the depressurized equipment values 6a and 6b during the cooling / heating operation are linked.

First, as shown in FIG. 1, both the first use side heat exchanger 8a and the second use side heat exchanger 8b are opened during the heating operation. Then
Further, the pressure reducing equipment values 6a and 6b are appropriately throttle-adjusted and controlled, and an appropriate amount of the refrigerant branches and flows into each of the use side units 31 and 32 as shown by a dotted arrow, and the first use side heat exchanger. 8a and the 2nd utilization side heat exchanger 8b perform a condensing action, heat-exchange with indoor air, output required heating capacity, and heat.

However, when the second user side unit 32 is not operating now but the first user side unit 31 is being operated, the pressure reducing device 6a is installed in the user side heat exchanger 8a of the first user side unit 31. A proper amount of the refrigerant narrowed down by the flow is operated. On the other hand, the reduced pressure equipment value 6b of the second usage side unit 32 which is not operated is restricted to a certain extent to restrict the refrigerant flow.

Driving is performed under these circumstances,
If the temperature sensor 15b arranged in the second heat exchanger 8b on the use side, which is not in operation, has a constant high temperature (for example, 50
C.) or higher is detected, the refrigerant is flowing in the refrigerant circuit 7b, which is not in operation, in an amount exceeding the limit amount, and the refrigerant condensing action (heating action) is performed. For this reason, in order to indicate that the refrigerant supplied to the operating first use-side unit 31 is in a shortage condition, the valve control device 20 receives the temperature signal, and first, the second valve in the non-operating state. Control is performed to close the second flow path opening / closing valve 9b of the usage-side unit 32. Then, after a lapse of a predetermined time (for example, 1 minute), control is performed to make the corresponding second reduced pressure equipment value 6b the minimum diaphragm condition, that is, the fully opened state. In this way, the second flow passage opening / closing valve 14b that is closed first prevents the refrigerant from flowing into the second usage-side unit 32 that is not in operation, and while the next second pressure reducing value 6b is open. The refrigerant that has accumulated in the refrigerant branch passage 7b downstream of the flow path opening / closing valve 14b and in the second usage-side heat exchanger 8b that is not in operation will flow away from the usage-side refrigeration circuit. Since the refrigerant also flows additionally to the first use-side heat exchanger 8a in operation, a sufficient amount of refrigerant can be secured in the operating refrigeration circuit, and the heating capacity is increased. It is possible to perform efficient heating that has a good start-up and can reach a desired temperature in a short time. Therefore, it is possible to avoid a situation in which a predetermined output cannot be ensured due to a shortage of the refrigerant in the circuit being operated due to the refrigerant pooling in the second usage-side heat exchanger 8b during the suspension of operation as in the conventional case.

In addition to the above-mentioned refrigerant flow control, if an inverter control type compressor 1 capable of variably controlling the operating speed is adopted, it is possible to effectively change the refrigerant cycle capacity,
The start-up performance during heating operation can be improved.

Next, the first user side unit 31 and the second
When changing from the state where both of the use side units 32 are operating to the operation of only the first use side unit 31,
When the operation progresses, the first utilization side unit 31 is sufficiently cooled and the refrigerant becomes excessive. In such a case, when the temperature sensor 15b detects the temperature indicated by the refrigerant evaporation action in the operation side unit 32 on the operation stop side, the second passage opening / closing valve 14b on the operation stop side is first opened. When opening from the beginning, it is kept open when it is opened from the beginning, and when it is slightly open, it is controlled to open larger.
After this, after a predetermined time, the corresponding second reduced pressure equipment value 6b is partially opened. As a result, the operating super-refrigerant can be gradually flowed and accumulated in the non-operating state. The stored amount can be controlled by setting the opening degree of the reduced pressure equipment value 6b from fully closed to fully open. Therefore, an appropriate amount of refrigerant can be made to flow to the operating unit 31 during operation, and the refrigerant can be effectively and economically used to perform comfortable cooling without overcooling.

Further, in the cooling operation, when one of the second usage side units 32 is stopped and only the first usage side unit 31 is operated, the room reaches the set cooling temperature. Although it is cooled, when the temperature sensor 15a on the side of the first utilization side heat exchanger 8a that is operating detects a temperature below a certain temperature (for example, 2 ° C.), the valve control device 20 receives the temperature signal and operates. Circuit 7b on the idle side that is not doing
The flow path opening / closing valve 14b is opened. After that, the valve control device 20 performs valve control such that the second reduced pressure device value 6b is partially (slightly) opened after a predetermined time (several seconds). this is,
The fact that the temperature sensor 15a detects a temperature equal to or lower than a certain temperature (for example, 2 ° C.) as the temperature of the refrigerant means that the cooling is sufficient and the amount of the refrigerant flowing to the operating side heat exchanger 8a is excessive. Therefore, by opening the flow path on-off valve 14b on the idle side which is not in operation, too much refrigerant is supplied from the operating unit 31 in operation while the circuit 7b is in operation.
By controlling the amount of the refrigerant to be bypassed to the open state of the second reduced pressure equipment value 6b from fully closed to fully open, the amount of refrigerant to be bypassed to the operating side heat exchanger 8a. To solve the problem of excessive refrigerant, eliminate the situation of overcooling, and provide comfortable cooling.

[0029]

As described above, according to the invention of claim 1, in the case where a part of the plurality of utilization side units to be operated is operated, each refrigerant circuit has When a pressure reducing value and a flow path opening / closing valve are provided, and the condensation action of the refrigerant is detected in the heat exchanger on the use side during operation suspension, the refrigerant flows into the circuit during operation suspension and unnecessary heating and Since it indicates that there is a shortage of refrigerant pool, the flow path on-off valve on the operation stop side is closed to prevent the inflow of refrigerant, and then the corresponding decompression device value is sufficiently opened to allow the accumulated refrigerant to flow away. Ensuring a sufficient amount of refrigerant in the operating unit during operation, improving the heating start-up operation, and stably producing the required heating output, and performing efficient and economical air conditioning operation You can

According to the second aspect of the present invention, in order to avoid the super-refrigerant in the operating unit on the operating side, if the evaporating action of the refrigerant is detected on the operating unit on the rest, the corresponding flow is detected. Since the valve opening / closing valve is opened and then the valve control equipment value is controlled so as to partially open the corresponding decompression equipment value, this allows the super refrigerant in the operating user side unit to operate while the super refrigerant is in operation. It can be stored in the heat exchanger to eliminate the super refrigerant condition. Therefore, the unit in operation can be operated at a comfortable cooling temperature.

Further, according to the third aspect of the present invention, in the cooling operation, if a low evaporation effect is detected in the operating unit on the operating side, it is judged that the operating state is due to excessive cooling of the refrigerant, and thus the operation is stopped. The flow control valve on the circuit that is operating is opened, and then the valve control is performed to open the decompression value appropriately, so that too much refrigerant is bypassed to the inactive user side unit. An appropriate amount of refrigerant that does not become supercooled can be made to flow, excess refrigerant can be eliminated, and economical and comfortable cooling temperature operation can be performed.

According to the invention of claim 4, at least one use side refrigeration circuit in which a reduced pressure value, a use side heat exchanger and a flow path opening / closing mechanism are respectively connected in series is provided, and the refrigerant flowing through each circuit is Based on the temperature or the temperature of the heat exchanger on the use side, the decompression value of each circuit is controlled from the fully closed state to the fully open state by the valve control equipment value, and the flow path opening / closing mechanism of each circuit is changed from the fully closed state. By controlling to the fully open state, the unit that is not in operation can be used to properly control the refrigerant circulation amount, and it is possible to reliably flow the required refrigerant to the unit that is in operation. Even when operating the unit, it can be effectively and efficiently operated.

Further, according to the invention of claim 5, the temperature of the refrigerant or the temperature of the heat exchanger on the utilization side is detected by using a temperature sensor or the like, and if the temperature signal is inputted to the valve control device value, each pressure reducing device is detected. The value and each flow path opening / closing mechanism operate to control the refrigerant circuit from fully closed to fully open so that a proper refrigerant flows, and a highly responsive and highly reliable refrigerant flow control can be performed.

[0034]

[Brief description of the drawings]

FIG. 1 is a refrigeration cycle diagram during a heating operation of an air conditioner according to the present invention which enables efficient operation by controlling a refrigerant flow.

FIG. 2 is a refrigeration cycle diagram during a cooling operation of the air conditioner according to the present invention, which enables more efficient operation than refrigerant flow control.

FIG. 3 is a refrigeration cycle diagram of a conventional air conditioner having a problem of a heating operation that is deficient in refrigerant and a cooling operation that is deficient in refrigerant.

[Explanation of symbols]

 1 Compressor 2 Four-way valve 3 Heat source side heat exchanger 6a 1st pressure reduction equipment value 6b 2nd pressure reduction equipment value 7a, 7b User side circuit 8a 1st user side heat exchanger 8b 2nd user side heat exchanger 14a 1st flow-path opening / closing valve 14b 2nd flow-path opening / closing valve 15a, 15b Temperature sensor 20 Valve control device

Claims (5)

[Claims] 1. An air conditioner comprising a refrigerant circuit in which a compressor, a heat source side heat exchanger, a pressure reducing device, a utilization side heat exchanger, and a flow path on-off valve are annularly connected in order by a refrigerant pipe. The compressor, the heat source side heat exchanger, the pressure reducing device, and the heat source side unit that mounts the flow path opening / closing mechanism, and the first use side unit that mounts the use side heat exchanger are separately mounted. , Second with a second user side heat exchanger
At least one unit of the use side heat exchanger is connected so that the second use side heat exchanger is in parallel with the use side heat exchanger in the refrigerant circuit, and the second side heat exchanger is connected in the refrigerant circuit of the heat source side unit. A second pressure reducing device and a second flow passage opening / closing valve are provided corresponding to the pressure reducing device and the flow passage opening / closing valve so as to control the flow of the refrigerant to the second use side heat exchanger,
Further, when the condensation operation of the refrigerant is detected in the usage side heat exchanger of the usage side unit that is not in operation, first the flow path opening / closing valve of the corresponding usage side heat exchanger is closed and then the corresponding decompression device is fully opened after a predetermined time. An air conditioner comprising a valve control device. 2. An air conditioner comprising a refrigerant circuit in which a compressor, a heat source side heat exchanger, a pressure reducing device, a use side heat exchanger, and a flow path on-off valve are annularly connected in sequence by a refrigerant pipe, wherein the refrigerant circuit is The compressor, the heat source side heat exchanger, the pressure reducing device,
A heat source side unit that mounts the flow path opening / closing mechanism and a first user side unit that mounts the user side heat exchanger are separately mounted, and a second user side heat exchanger is mounted. At least one unit of the use side unit is connected such that the second use side heat exchanger is parallel to the use side heat exchanger in the refrigerant circuit, and the second side heat exchanger is provided in the refrigerant circuit of the heat source side unit. A second pressure reducing device and a second flow passage opening / closing valve are provided corresponding to the pressure reducing device and the flow passage opening / closing valve so as to control the flow of the refrigerant to the use side heat exchanger, and the operation is suspended. When the use side heat exchanger of the side unit detects the evaporating action of the refrigerant, the flow control valve of the corresponding use side heat exchanger is first opened, and after a predetermined time, the corresponding pressure reducing device is partially opened. An air conditioner characterized by that. 3. An air conditioner comprising a refrigerant circuit in which a compressor, a heat source side heat exchanger, a pressure reducing device, a utilization side heat exchanger, and a flow path on-off valve are annularly connected in order by a refrigerant pipe. The compressor, the heat source side heat exchanger, the pressure reducing device, and the heat source side unit that mounts the flow path opening / closing mechanism, and the first use side unit that mounts the use side heat exchanger are separately mounted. , Second with a second user side heat exchanger
At least one unit of the use side heat exchanger is connected so that the second use side heat exchanger is in parallel with the use side heat exchanger in the refrigerant circuit, and the second side heat exchanger is connected in the refrigerant circuit of the heat source side unit. A second pressure reducing device and a second flow passage opening / closing valve are provided corresponding to the pressure reducing device and the flow passage opening / closing valve so as to control the flow of the refrigerant to the second use side heat exchanger,
In addition, when the evaporating action of the refrigerant is detected in the heat exchanger on the user side of the user side during operation, first open the flow path on-off valve of the heat exchanger on the user side during operation stop, and then after a predetermined time, the user side after operation stop An air conditioner comprising a valve control device for partially opening a decompression device of a heat exchanger. 4. An air conditioner comprising a refrigerant circuit in which a compressor, a heat source side heat exchanger, a pressure reducing device, a use side heat exchanger, and a flow path opening / closing mechanism are annularly connected in order by a refrigerant pipe. At least one refrigerant circuit in which the device, the second usage-side heat exchanger, and the second flow path opening / closing mechanism are serially connected in series by refrigerant piping
Circuit connected in parallel with the use side heat exchanger and flowing through the use side heat exchanger or the refrigerant flowing through the use side heat exchanger and the second use side heat exchanger or the use side heat exchanger Valve control for controlling the opening degree of the decompression device and the second decompression device from fully open to fully closed and the fully closed or fully opened state of the flow path opening / closing mechanism and the second flow path opening / closing mechanism based on the temperature of the refrigerant. An air conditioner comprising a device. 5. The pressure reducing device, the second pressure reducing device, the flow path opening / closing mechanism, and the second flow path opening / closing mechanism all control the flow path of the refrigerant from fully open to fully closed in response to a signal. The air conditioner according to claim 1, which is characterized in that.